Restarting problem in Samsung Wave 525

I purchased a samsumg mobile fone on 22nd december 2010 model gt s5253 name samsung wave525 worthrs 7500/= But within a week I discovered that hands free wasn't working so I went to service center nd it was repaired under warranty n then the charging jack nd headset jack stopped working ...then again I had 2 visit samsung care for the service .Now again the fon has a new problem infact various problems . Problems are given in details 1.Phone restarts on its own any time without nay notice 2.It hangs wen working on it . 3.Battery is not functioning upto the mark 4.It gets heated up very early even wen not in use or when under charging . Plzzz suggest me what should I do now...warranty will be getting over in few months ....

I have a problem relating to sos message setting. I am unable to solve by doing switch offf and again on. I am troubling lot due to this problem.How to remove this setting please tell me. Because due to this I have no network so I cant contact to anyone and at the same time no one can contact me.My model no ID samsung wave 525. So please give me reply urgently.